Air conditioning system utilizing



' which the moisture can condense.

Patented Jan. 5, 1943 AIR CONDITIONING SYSTEM UTILIZING REFRIGERATIONRobert T. Palmer, Sharon, Mass., assignmto B. F. Sturtevant Company,Boston, Mass.

Application August 17, 1940, Serial No. 352,991

2 Claims.

This invention relates to air conditioning systems utilizingrefrigeration and provides through refrigeration, the simultaneouscooling and c eaning of air.

To provide proper air conditions in an air conditioningsystem involvesmore than air movement and adjustment of the temperature and humidity ofthe air. For the apparatus ordinarily used for moving the air andadjusting its temperature, does not clean it properly; does notsterilize it, and does not remove objectionable odors. For additionallycleaning the air electrostatic precipitators are used; for sterilizingthe.

air ultraviolet lamps are used. and for removing odors, ozone producingdevices are used.

This invention accomplishes proper cleaning, sterilizing and odorremoval through the use of the refrigeration apparatus forming a part ofa time the moisture condenses upon the solid particles and falls outfrom the air inthe form of rain. The temperature at which this actiontakes place is fairly critical for if the temperature of the air isreduced low enough the moisture will condense out even if there are nosolid particles upon However the conditions are right for the moistureto condense upon solid particles suspended in the air, when thetemperature is reduced to the point at which fog forms at which pointthe temperature will beat or near the dew point temperature of the air.

This invention adds what may be termed a fog" or cloud chamber to an airconditioning system utilizing refrigeration for air cooling, and

utilizes the refrigeration apparatus for producing a fog in said chamberwhereby the solid particles suspended in the air. entering the chamberare removed in the form of rain. The air who treated is first moistenedin an air washer, bythe introduction of steam or otherwise; the largersolid particles in the air are removed by the washing action and byfilters; the entrained moisture is removed and the air then,enters thefog chamber where its temperature is reduced to the fog forming pointand held there so that fog persists in the fogv chamber at all times.Water droplets form upon the solid particles, including organic odorparticles and bacteria,

out of the air in the form of rain. The air then may be chilled in afollowing step to the temperature at which it is to be supplied in thespace served, in which additional step the air may be chilledsufficiently for any desired dehumidification to take place and the airthen reheated if desirable.

An object of the invention is to clean air by refrigeration.

A more definite object of the invention is to utilizethe refrigerationapparatus of an air conditioning system for removing the very smallsolid particles suspended in the air.

The invention will now be described withreference to the drawing, ofwhich:

Fig. 1 is a diagrammatic view or an air conditioning system embodyingthis invention;

Fig. 2 is a diagrammatic view of another embodiment of the invention,and

Fig. 3 is a diagrammatic view of a. photo-electric control which may beused for maintaining a fog in the fog chamber of Fig. 1. Referring nowto Fig. 1, the fan 5 moves the air to be conditioned through themoistening chamber 6, the fog chamber 1, the dehumidifying chamber 8,and discharges it into the space served.

The moistening chamber 6 may be an air washer of the type disclosed inthe R. E. Keyes Patent No. 2,199,632 of May 7, 1940 which isparticularly suitable for cleaning the air of the larger solid particlescarried thereby, and for eliminating entrained moisture. spray water berefrigerated as refrigeration is employed in following steps. may berefrigerated though if desired, or it may be warm water, or steam may beused.

The fog chamber I may contain the rows of refrigerant tubes 9 placedalong opposite sides thereof and supplied by refrigerant from the sourceI0 through the pipe I I, the adjustable valve l2 and thethermostatically controlled valve l3, the refrigerant being returned tothe source 10 through the pipe H.

The dew point thermostat l5 responds to changes in the dew pointtemperature of. the air entering the fog chamber 1 and adjusts the valvemotor l6 of the valve l3 for varying the temperature of the tubes 9,conformably therewith. Since the air entering the fog chamber may besaturated, the thermostat l5 then may be a wet bulb thermostat.

A port I! is provided for observation within the fog chamber, theinterior of which may be suspended in the air in the fog chamber andfall illuminated so that the formation of fog may be It is not necessarythat the The spray water density in the chamber 9. Or the thermostat I5may be biased to accomplish this.

the photo-electric cell control could act in the embodiment of Fig. 2 toadjust thedamper 28 towards closed position when fog of the desiredMoisture will condense upon the small solid particles suspended in theair in the fog chamber, and the droplets so formed will fall intothe umpof the chamber 9 from which they may e drained into a sewer. The abovedescribed ontrols may be adjusted for providing the proper og densityfor accomplishing this.

The air leaving the fog chamber may or may not have the desired lowtemperature and dew pointand so the dehumidifying chamber 8 is providedfor chilling the clean air. ber contains the refrigeration coil 20 andthe refrigeration supplied by the source 10 to the coil may becontrolled by the dew point thermostat 2| which adjusts the motor 22 ofthe valve 23 in the refrigerant supply pipe 24.. The thermostat 2| maybe set to maintain a predetermined dew point temperature below that ofthe dew point temperature of the air entering the chamber 8 forproviding the desired degree of dehumidification;

In the embodiment of Fig. 2, the chilling of the air in the fog chamberfor the production of fog, is accomplished by mixing warm moist air fromthe chamber 6 with" chilled air from the air chilling chamber 26. Thevolume of chilled air is controlled by the thermostat l5 which adjuststhrough the motor 21, the position of the damper 28. The motor 21 may bebiased by the hand control 29 for causing it to act to maintain thedesired fog in the chamber 9.

The control of Fig. 3 utilizes a photo-electric cell for maintaining afog in the fog chamber 9. The light source 30 is placed at one side ofthe chamber 9, and the photo-electric cell pansion valve 31, and thepipe 38, to evaporator tubes in the chamber 9.

Instead of using the separate compressor of Fig. 3, the photo-electriccell could act to open and close the valve l3 in the refrigerant supplypipe H in the embodiment of Fig. 1 Likewise This charndensity appears inthe fog chamber.

The, controls illustrated are well known to those skilled in the art andso have not been described in detail herein. They may be actuatedelectrically, by compressed air or hydraulically as such controls arereadily available.

The refrigeration source employed may be a' compressor-condensercombination utilizing any Well known'vqlatile refrigerant or may be anyother suitable source employing if necessary, a pump. The cooling effectmay be controlled by compressor control, by mixing valves or in anyother well known manner.

This invention is applicable to winter as well as summer airconditioning. In a winter conditioning system, the dehumidifying chamber8 would be unnecessary.

, While the invention has been described as embodied in an airconditioning system, it could I of course be used alone in a cleaningsystem complete in itself, as illustrated for example, by Fig. 3. Thecontrols of Figs. 1 or 2 could be used in substitutionfor orcomplementary to the photo-electric control of Fig. 3.

While embodimentsof the invention have been described for the purpose ofillustration; it should be understood that the invention is not limited-to the exact apparatus and arrangement of ap- Y air moistener, a fogchamber for receiving air from said .moistener, a source oirefrigeration connected to said chamber for chilling the air therein,and means including means responsive to changes in the dew pointtemperature of the air entering said chamber for regulating the re-,frigeration from said source to maintain a fog in said chamber bydecreasing the refrigeration upon increase in the dew point temperatureand by increasing the refrigeration upon decrease in the dew pointtemperature.

- is present.

2. An air conditioning system comprising an air moistener, a fog chamberfor receiving air from said moistener, a source of refrigerationconnected to said chamber for chilling the air therein, and meansincluding photo-electric means responsive to the presence of fog in saidchamber for regulating the refrigeration from said source to maintain afog in saidchamber by decreasing the refrigeration when fog appears andby increasing the refrigeration when no fog ROBERT PALMER.

